Le Friday 14 Oct 2016 à 14:10:07 (+0100), Dietmar Eggemann a écrit : > On 14/10/16 09:24, Vincent Guittot wrote: > > On 13 October 2016 at 23:34, Vincent Guittot <vincent.guit...@linaro.org> > > wrote: > >> On 13 October 2016 at 20:49, Dietmar Eggemann <dietmar.eggem...@arm.com> > >> wrote: > >>> On 13/10/16 17:48, Vincent Guittot wrote: > >>>> On 13 October 2016 at 17:52, Joseph Salisbury > >>>> <joseph.salisb...@canonical.com> wrote: > >>>>> On 10/13/2016 06:58 AM, Vincent Guittot wrote: > >>>>>> Hi, > >>>>>> > >>>>>> On 12 October 2016 at 18:21, Joseph Salisbury > >>>>>> <joseph.salisb...@canonical.com> wrote: > >>>>>>> On 10/12/2016 08:20 AM, Vincent Guittot wrote: > >>>>>>>> On 8 October 2016 at 13:49, Mike Galbraith <efa...@gmx.de> wrote: > >>>>>>>>> On Sat, 2016-10-08 at 13:37 +0200, Vincent Guittot wrote: > >>>>>>>>>> On 8 October 2016 at 10:39, Ingo Molnar <mi...@kernel.org> wrote: > >>>>>>>>>>> * Peter Zijlstra <pet...@infradead.org> wrote: > >>>>>>>>>>> > >>>>>>>>>>>> On Fri, Oct 07, 2016 at 03:38:23PM -0400, Joseph Salisbury wrote: > > [...] > > >>> When I create a tg_root/tg_x/tg_y_1 and a tg_root/tg_x/tg_y_2 group, the > >>> tg_x->load_avg > >>> becomes > 6*1024 before any tasks ran in it. > >> > >> This is normal as se->avg.load_avg is initialized to > >> scale_load_down(se->load.weight) and this se->avg.load_avg will be > >> added to tg_x[cpu]->cfs_rq->avg.load_avg when attached to the cfs_rq > > Yeah, you right, even when I've created 50 second level groups, > tg_x->load_avg is ~6800. > > Could it have something to do with the fact that .se->load.weight = 2 > for all these task groups? on a 64bit system?
I don't think so, the problem really comes from tg->load_avg = 381697 but sum of cfs_rq[cpu]->tg_load_avg_contrib = 1013 which is << tg->load_avg and cfs_rq[cpu]->tg_load_avg_contrib == cfs_rq[cpu]->avg.load_avg so we can't expect any negative delta to remove this large value > > In case we call __update_load_avg(..., se->on_rq * > scale_load_down(se->load.weight), ...) we pass a weight argument of 0 > for these se's. > > Does not happen with: > > - if (shares < MIN_SHARES) > - shares = MIN_SHARES; > + if (shares < scale_load(MIN_SHARES)) > + shares = scale_load(MIN_SHARES); > > in calc_cfs_shares(). > > [...] > >
